Philip Ball at Marginalia Review:
The term “soft matter” was coined in 1970, and has become common currency in science only in the past two or three decades. Yet the substances to which it refers – such as honey, glue, flesh, soap, leather, starch, bitumen, milk, pastes and gels – have been familiar components of our material world since antiquity. The phrase, incidentally, was coined by French scientist Madeleine Veyssié, a collaborator of physics Nobel laureate Pierre-Gilles de Gennes, one of the foremost pioneers of the field. The French term, matière molle, is something of a double entendre, which would doubtless have appealed to the suave and charismatic de Gennes, well known for his almost stereotypically Gallic romantic liaisons.
Modern theories that describe the molecular-scale nature of gases, simple liquids and solids were all taking shape by the end of the nineteenth century. But the sticky, viscous, rubbery or bendy fabrics of soft matter were not properly tackled until researchers such as de Gennes and Cambridge physicist Sam Edwards gave them serious attention in the 1970s and 80s; for many centuries they had been all but excluded from the conventional trio of the states of matter.